1. HIGH RESOLUTION SPECTROSCOPY OF THE TWO LOWEST VIBRATIONAL STATES OF QUINOLINE C 9 H 7 N O. PIRALI, Z. KISIEL, M. GOUBET, S. GRUET, M.-A. MARTIN-DRUMEL, A. CUISSET, F. HINDLE, G. MOURET Institut des Sciences Moléculaires d’Orsay, CNRS-Université Paris-Sud AILES beamline, synchrotron SOLEIL Institute of Physics, Polish Academy of Sciences, Warszawa, Poland; Laboratoire PhLAM, Université de Lille 1, Villeneuve de Ascq, France Laboratoire de Physico-Chimie de l’Atmosphère, Université du Littoral Côte d’Opale, Dunkerque, France.

2. Low energy vibrational states of quinoline GS A’ 44 A’’ (178 cm -1 ) 45 A’’ (168 cm -1 ) Prolate asymmetric top µ a =0.2 D and µ b =2.1 D 45 vibrational modes (31 A’ and 14 A’’) GS constants from Kisiel et al., JMS, 217 (2003) 0 170 cm -1 2 45 (338 cm -1 ) 2 44 (355 cm -1 ) 45 + 44 (347 cm -1 ) 43 (392 cm -1 ) 43 (378 cm -1 ) 350

3. FT-FIR spectroscopy (SOLEIL) : 45 – GS band P branch R branch - Spectral resolution = 30 MHz -Determination of E 45 -Rough values of A, B, C ES constants -E 45 - E 44 separation

4. Sub-mm spectroscopy (LPCA+Warsaw): - 140-220 GHz spectral range - 30 kHz line accuracy -b-type pure rotation in the GS, 45, 44 -Interstates transitions -GS transitions - 45 transitions - 44 transitions

5. FTMW spectroscopy (PhLAM): ES transitions in the jet 45 44 Spherical moving mirror MW Radiation Gas injection L-shaped antenna Vacuum : ≈ 10 -6 mbar Step by step motor Stainless steel cell Spherical mirror (Aluminum) Pumping group Pulsed nozzle Gaussian beam profile W 0 = 42 mm à 12 GHz 1200 mm Supersonic Jet About 55 b-type transitions within 45 and 44 ES transitions are 1000 less intense than the corresponding GS transitions 25 GS a-type transitions Frequency accuracy better than 2 kHz

6. Spectral analysis and identification of several perturbations Use of AABS, LWW, and SPFIT/SPCAT softwares to analyse all the data -2 clear series of interacting levels with  Ka=2 -Other pertubed levels with unidentified perturbing partner 45 44

7. Hamiltonian : Watson A reduction and I r representation

8. 45 E 45 5049310.(47) A 3141.723(10) B 1271.9959(11) C 906.4587(11) JJ 0.0191541(71)  JK 0.056545(79) KK 0.08473(12) JJ 0.00596471(64) KK 0.0593138(77) 44 E 44 -E 45 277935.(94) A 3142.092(10) B 1271.6425(11) C 906.4012(11) JJ 0.0192330(70)  JK 0.037301(79) KK 0.23231(12) JJ 0.00535848(62) KK 0.0609730(72) Results of the fit for 45 and 44 45 / 44 Gc 107.701(37) Gc J ‐0.0003270(16) Gc K ‐0.001388(13) Fab [ 0.] Wf 22652.(288) Wf J ‐0.5218(19) Wf K 5.5069(26) WW [ 0.] WJWJ WKWK ‐0.000003605(29) GS A 3145.533086(71) B 1271.578056(61) C 905.739457(38) JJ 0.0191129(28)  JK 0.0470270(89) KK 0.161469(18) JJ 0.0056627(13) KK 0.060613(22) Lines RMS RMS errorJ’’ rangeK a ’’ range GS 258 0.028 MHz 0.951-1430-58 45 3012 0.048 MHz 0.812-1480-58 44 2999 0.048 MHz 0.811-1300-58 45 - GS 3578 0.0002 cm -1 1.029-1149-60

9. E 45 – E GS 5047475.91(13) E 44 – E 45 281603.51(13) A 3141.723(10) B 1271.9959(11) C 906.4587(11) Intercorrelation between parameters ES rotational parameters A 3142.092(10) B 1271.6425(11) C 906.4012(11) Fermi parameter and vibrational energies 45 44 (A1+A2)/2 3141.907426(29) (B1+B2)/2 1271.819307(15) (C1+C2)/2 906.429956(13) (A1-A2)/2 ‐0.188(10) (B1-B2)/2 0.1771(10) (C1-C2)/2 0.0292(11) 45 5049310.(47) 44 – 45 277935.(94) WFWF 22652.(288)

10. Conclusions Use of very complementary techniques to study the rotational structure of GS, 45, and 44 Observation of perturbations in the rotational levels of 45 and 44 Similar difficulties might be encountered in the IR spectra of many PAHs molecules Seems difficult to detect in the c-type transitions recorded by FTIR techniques Analysis of the pure rotation transitions observed within the next vibrational polyad seems rather difficult Acknowledgments Beamtime allocation 20131274 ANR grant “GASPARIM”